1. Field of the Invention
The invention is related to a touch apparatus, and more particularly, to an optical touch apparatus.
2. Description of Related Art
With the development of optoelectronic technology, a user's requirements may no longer be satisfied by using a mouse to control objects in a computer and a screen. Hence, interfaces more user-friendly than the mouse have been gradually developed. In these user-friendly interfaces, the touch method by using fingers is closest to human experiences in the daily life. In particular, it is easier for elders and children to touch an object with fingers than the mouse. This has been partially proved by the adoption of the touch screen in some automatic teller machines.
In addition, for a conventional laptop, if no mouse is externally connected, a touch pad and a track point next to the keys are usually used to control the cursor. However, controlling the cursor by the touch pad or the track point next to the keys may not be easier than a mouse for normal users. A touch panel disposed on the monitor is able to solve such problem. Because the control method of the touch panel is an intuitive control method, in which the user directly touches the monitor to control the objects. Therefore, when the touch panel is applied to the laptop, even if the operating conditions make the user inconvenient to externally connect the mouse, the user is capable of agilely operating the laptop by the touch panel.
Currently, touch panels are roughly classified into resistive-type, capacitive-type, optical-type, acoustic-wave-type, and electromagnetic-type. Generally, an optical-type touch panel includes a display, a light source, a light guide unit, a detector, and a processor. The light source is disposed next to a display area to generate a beam. The beam passes through the light guide unit and then is detected by the detector. When an object touches the panel, the processor determines a position of a touch point according to a change in light intensity detected by the detectors. In addition, the uniformity of the luminance of the beam passing through the light guide board affects the accuracy in determining the touch point. The more uniform the luminance is, the higher the accuracy is. However, according to prior art, the luminance of the beam passing through the light guide board is non-uniform, so that the accuracy in determining the position of the touch point is also lower.